Individuals and habits are all different, and so the specifics of diagnosing and changing the patterns in our lives differ from person to person and behavior to behavior. Giving up cigarettes is different than curbing overeating, which is different from changing how you communicate with your spouse, which is different from how you prioritize tasks at work. What’s more, each person’s habits are driven by different cravings. When we do something results in some pleasure or reward, we find our hearts inclined to do that again. Repeating this over and over again creates a new habit. Many habits are created not by us but our circumstances and others’ contributions. However we can consciously design habits and nurture them. That’s what character building and nurturing personality is about.

Most of the choices we make each day may feel like the products of well-considered decision making, but they’re not. They’re habits. This segment explains why habits exist, and how they work. At the core of every habitual pattern is a habit cycle.

The habit cycle is composed of three basic steps. First, there is a cue, a trigger that tells your brain to go into automatic mode. The cue can be internal, such as a feeling or thought, or external, such as a time of day or the company of certain people (which is why it’s easier to exercise among our running buddies, but harder to study when our friends are in the library).

The second part of the habit cycle is the routine, the behavior that leads to the reward. The routine can be physical (eating a burger), cognitive (“remember for the test”), or emotional (“I always feel anxious in math class”).

The third part is the reward. Not surprisingly, the reward can also be physical (sugar), cognitive (that’s really interesting), or emotional (I always feel relaxed in front of the TV). The reward determines if a particular habit cycle is worth remembering.

Rewards are powerful because they satisfying cravings. But we’re often not conscious of the cravings that drive our behaviors. To figure out which cravings are driving particular habits, it’s useful to experiment with different rewards. This might take a few days, or a week, or longer. During that period, you shouldn’t feel any pressure to make a real change – think of yourself as a scientist in the data collection stage.

Addicts in recovery learn early that they almost never drink for the intoxication, but because it helps them access certain rewards: relief from work stress, escape from worries, or freedom from social anxiety.

The basal ganglia, a small region of the brain situated at the base of the forebrain, play an important role in stored habits. Interestingly, scientists have discovered that mental activity in this part of the brain actually decreases as a behavior becomes more habitual. When a habit emerges, the brain become more efficient (and needs fewer resources) because automatic patterns take over.

This stresses that understanding how habits work-or, understanding the habit cycle-makes them easier to control. By changing the cue or the reward in a habit cycle, you can change the pattern of behavior.

Cue and a reward, on their own, are not enough to make a habit last. The cue, in addition to triggering a routine, must also elicit a craving for the reward. Only when your brain starts anticipating-or craving-the reward, will the behavioral pattern become automatic. (That’s why, even if you’re not hungry, once you see a plate of sandwiches it’s so easy to automatically pick one up.)

The golden rule of habit change says that to change a habit, it is impor­tant to keep the cue and the reward the same, while inserting a new routine into the habit cycle. It sounds easy in theory, but given the strength of most habit cycles, changing behaviors can be very difficult.

Once you’ve figured out your habit loop – you’ve identified the reward driving your behavior, the cue triggering it, and the routine itself – you can begin to shift the behavior. You can change to a better routine by planning for the cue, and choosing a behavior that delivers the reward you are craving. What you need is a plan.

In the prologue, we learned that a habit is a choice that we deliberately make at some point, and then stop thinking about, but continue doing, often every day.

Put another way, a habit is a formula our brain automatically follows: When I see CUE, I will do ROUTINE in order to get a REWARD.

To re-engineer that formula, we need to begin making choices again. And the easiest way to do this, according to study after study, is to have a plan. Within psychology, these plans are known as ‘implementation intentions.’

Obviously, changing some habits can be more difficult. But this framework is a place to start. Sometimes change takes a long time. Sometimes it requires repeated experiments and failures. But once you understand how a habit operates – once you diagnose the cue, the routine and the reward – you gain power over it.